1. Field of the Invention
The invention relates to integrated circuits, and more particularly, to an integrated circuit with automatic configuration and method thereof.
2. Description of the Related Art
SOCs (system on chip) generally integrate a lot of functions. Therefore, some SOCs are “initialized” or “set up” via configuration pins to configure the SOCs into specific modes of operation or to provide the SOCs with default values during power-on or hardware reset. FIG. 1 is an exemplary diagram showing a conventional SOC 100. In the SOC 100, a first controller 110 and a second controller 120 share a common port 142 via the multiplexer 140 and therefore they cannot be enabled at the same time. Here, the port 142 is an M-pin port (M is a positive integer). When the reset signal is asserted, strap signals containing default values and/or a selection of an enabled controller are written into the strap register 130 via the strap pin 132. After reset, a default configuration is in effect and the strap pin 132 takes on its second role to operate. Assuming that the first controller 110 is selected according to the default configuration. The strap register 130 asserts an enable signal e1 to enable the first controller 110 and de-asserts an enable signal e2 to disable the second controller 120. In the meantime, the strap register 130 generates a corresponding switching signal CS to the multiplexer 140 to allow the first controller 110 to access all the pins on the port 142.
However, the SOC is space consuming and cannot spare many dedicated pins (i.e., strap pins or configuration pins) for the default configuration. Accordingly, what is needed is an integration circuit and method to address the above-identified problems. The invention addresses such a need.